Network Ten has fixed security flaws in the Big Brother 2007 Web site that compromised the personal details of registered users.
The technical problems, which began immediately upon the site's launch on Sunday night, exposed such details as users' names, e-mail addresses, postal addresses and mobile phone numbers.
While there were no specific details on what went wrong, Ten stressed that no credit card information or other financial data was exposed.
"All credit card details are absolutely secure, and the Big Brother Web site employs industry-standard SSL protection for credit card entry," said Damian Smith, general manager of Digital Media at Ten. "No data from credit cards is stored at any time on any TEN or BB07 servers."
The broadcaster will be contacting users whose privacy was breached over the coming 36 hours to "explain what happened, what we've done to repair it, and how we'll deal with the situation," Smith told ZDNet Australia.
"Our website security is provided by GeoTrust SSL Security. GeoTrust is the world's second largest digital certificate provider, and a leader in a wide variety of Identity and Trust services. We use 128 bit encryption for your credit card details, which is the highest form of encryption for web use.
"Our credit card processing is provided by Dialect Payment Technologies who have two of the top three global card companies using their services, and nearly 40 banks around the world as customers," the Big Brother Web site stated.
Ten's initial response to the problem was to shut down the registration process and offer premium content (which usually costs $39.95 per season) to all visitors until the technical problems were addressed.
The broadcaster is now offering a refund to its premium subscribers and an additional 17 days of access to premium content for members who had paid for the AU$7.95 fortnightly pass.
For new users, Ten is offering its premium season pass at a reduced rate of AU$36.95.
"Despite extensive testing of all aspects of the BB07 Web site in the days prior to launch, the failure was not found until after launch," Smith said.
"Network Ten apologises for the inconvenience and effect that this has had on [BB07] users. We have worked around the clock since Sunday to repair the failure, and wish to offer customers a firm commitment that the problem will not recur. We take our obligations under privacy legislation and guidelines very seriously, and will work to restore users' trust."